Pallet unloading machine



July 12, 1960 Filed March 12, 1956 F. Wl FENTON PALLET UNLOADING MACHINE'7 Sheets-Sheet 1 BY 9M ATTORNEY July 12, 1960 F. w. FENToN 2,944,702

PALLT UNLOADING MACHINE Filed Maron i2, 195e 7 sheets-sheet 2 FIG. I9

FIG.3

INVENTOR.`

ATTORNEY FRANK W. FENToN July 12, 1960. F. w. Fr-:N'roN v 2,944,702

PALL'T UNLOADING MACHINE:

Filed March 12, 1956 7 Sheets-Sheet 5 FRANK W. FENToN ATTORN EY 7Sheets-Sheet 4 N .m RN. mi m mW .N K AN MI A R n FQ. V. B QN Qn. 1.0i

ATTORNEY July 12, 1960 Filed March 12. 1956 7 Sheets-Sheet 5 Filed Marchl2, 1956 INVENToR. FRANK W. FENToN BY Y ATTORN EY July 12, 1960 F. w.FENTON 2,944,702

PALLET UNLOADING MACHINE Filed March 12, 1956 '7 Sheets-Sheet 6 ATTORNEYJuly l2, 1960 F. w. FENTON PALLET UNLOADING MACHINE 7 Sheets-Sheet 7Filed March 12, 1956 MMM t 2,944,702 PALLET UNLoADING MAcmNE Frank W.Fenton, Lemay, Mo., assignor to Beacon Production Equipment Corporation,Centreville Township, a corporation of Illinois FiledMamz, 1956, ser.No. 511,058 Y 2o Claims. (omai- 13) Y This invention relates in generalto materials handling equipment, and more particularly, to a palletunloading' machine.

The use of loading pallets for all types of merchandise has now become amost commonplace expedient in industry, such pallets being adapted forready handlingV byl forkliftV trucks and hence providing a supportplatformV for a full lo'ad which can be easily transported from point topoint. Heretofore, many elorts have been made for the automatic loadingof pallets, that is, the stacking ofV Yarticles thereon in a prearrangedmanner, so as to obviate the need of manual labor for such purpose.However,

in certain industries there has developed the need for thev automaticunloadingof articles andl the like from pallets. A particular examplevisthe beverage industry wherein empty bottles are continuously returned tothe bottling companies in cartons. As such cartons .are received fromthe various returning agencies the same are manually stacked uponpalletsforeasy handling. At the plant said cartons'v must be removedfrom the pallet so that the bottles may in turn be withdrawn therefromfor cleansing and refilling. Up to the present such vpallets have beenunloaded manually causing a considerable labor costas well as theattendant expenditure of time. There are other numerous industries whichrequirer the unloading o'f pallets, but the reference to the beverageindustry has been cited merely for exemplary purposes.

Also, in conjunction with the loading of pallets there have developedvarious article arrangements, so as to create what is termed inindustry, a locked load. This has reference to articles of a non-cubiccharacter, disposed in tiers, wherein certain of the articles in-o'netier are disposed at 90 Yto other articles in the same tier, with l theadjacent upper and lower tiers having a reverse pattern so as to renderthe load cohesive and unitary. The

variety of patterns to create locked loads are myriad.

Consequently, in the unloading V'of pallets. containing,

cartons and the like in locked patterns, the particular disposition ofthe rvarious cartons mustvbe taken intoconsiderationso that the samewill berproperlyv'presentedj after unloading.

Therefore, it 'is a primary object of the present invention to provide amachine which will automatically yun-y lo'ad a fully loaded pallet. j Y

It is another object of the present invention to provide a palletunloading machine which is adapted to unload pallets' supportingarticles and the like stacked in' any number of tiers and which machinewill effectively accommodate such articles as arranged in lockedpatterns. Y

lt is an additional object of the present invention to v provide apallet unloading machine havinguniquemeans A for preventing obstruction,such as jamming and the like,

of the articles as the same are unloaded.

It is another lobject of the present invention to provide i `line' 6-6of Figure 5. a Y Figure 7 is a horizontal transverse section taken online 19.-19 of Figure 2.

, 2,944,762 Patented July 12, 1960 provide a pallet unloading machinewhich may be eco-' nomically produced; which is so Vconstructed as to beresistantto breakdown; which can unload pallets in minimum time; andwhichis durable in usage.

These and other detailed objects are obtainedr by the structures'illustrated inthe accompanying t drawings' (seven sheets) in which- YFigure 1 is a front endY view of a palletunloading machine constructedin accordance with and embodying the present invention.

Figure 2 is a side view of the machine. Figure 3 is a top plan view ofthe machine. Figure 4 is a vertical transverse line 4-4 of Figure 2. f

Figure 5 is a vertical transverse section taken on the line 5-5 ofFigure 4.

Figure 6 is a fragmentary vertical section taken on the the line 7--7Yof-Figure 2.v

Figure 8 `is an enlarged lvertical sectio'n line 8--8 of Figure 2. l

taken on the Figure 9 is a vertical transverse section taken on line 9 9of Figure 8.

' Figure 10 is anenlarged, top plan view of thedischarge l conveyor. v YY I Y Figure l1 is a front view of the discharge conveyor.

. Figure l2 is a vertical transverse section taken on;

the line 12--12'of FigurelO.

Figure 13 is a vertical transverse section taken on the line 13-13 ofFigure 10.

Figure 15 is a horizontal transverse section taken on the line 15-15 ofFigure y14. v

Figure 16 is an enlarged side view of a carton stripper carrier.. Y

Figure 17 is a vertical transverse section taken on the line1717 of`Figure 16.

Figure 18 is a view taken on the line 18-18 of Figure 16.

Figure 19 is a vertical transverse section taken on the VFigure 20 is awiring diagram -of .the ing the machine. v

ation of the system for the Vstripper assembly motor and clamping barfluid cylinder. l

' In essence the present invention comprises a machine l for receiving afully loaded pallet p having cartons in out types of articles other thanspeciiically cartons, but herein the load elements will be shown asnon-cubic cartons for illustrative purposes only, and hence to faciliIitate comprehension as to the versatility of Ithe machine.

The machine is adaptedv to effect transfer ofthe cartons from thepallet'onto a discharge conveyor vso-that the` i load is thus reduced toits unit constituents for ultimate processing and handling. The cartonsare removed from the Vuppermost tiers downwardlyHand-delivered tothesection taken on the circuitfor operat- Y vFigures 2l, 22, and 23AVschematicallyr illustrate theY `operation of the system for theelevatorflluid cylinders.-

Figures 24, 25 and 26 schematically illustrate the oper- Y- conveyor byrows. After the top tier has been stripped from the load, the pallet iselevated to present the next tier into position for carton removal. Thedischarge conveyor is inclined transversely s o that the cartonsreceived thereon will be displaced downwardly from the next succeedingrow to prevent any untoward interfering or impeding contacttherebetween. Incorporated in the discharge conveyor is a carton turningunit so that all cartons travelling from the discharge conveyor will beaxially aligned for transfer to a delivery conveyor.

It should be noted that it is present practive to stack non-cubiccartons` and like articles on pallets in what is called a lockedformation wherein one tier will contain several cartonsl arranged inaxial normal relationship to the remaining cartons, withY the adjacentupper and lower tiers having a reversed pattern, with the total loadassuming a cohesive, well-knit unit. The machine of this invention isadapted to, handle, pallets having cartons arranged in any particularlocked formation.

In the drawings which illustrate the preferred embodiment of the presentinvention, A `refers to a pallet unloading machine having a rectangularbase frame 1 com prised of parallel; side and end members 2, 2 and 3,3', respectively, as of I beams or channels. Provided upon base frame 1at the front end thereof is a housing 4 having side walls 5, 5', a frontend wall 6 and a rearward end. wall 7, whichk isk of greater height thansaid front end wall 6; there being a plurality of uprights 8,` welded tothe base frame 1 for supporting said housing walls. Extending upwardlyand rearwardly from the upper edge of housing front wall 6 is atop wall9, the rearward edge portion being secured to the forwardly presentedface of housing wall,7 at a point beneath its upper end thereby defininga projecting section 7' of saidwall 7. The degree of inclinationto thehorizontal of top wall 9 is preferably approximately 22.

Mounted on frameside member 2 spacedly from housing side wall 5' todefine therebetween an infeed opening B isV a narrow, vertical panel orplate 11 of suitable sheet, stock extending upwardly above housing 4 andbeing secured, as by welding, along its rearward side edge totheadjacentfmargin of a backing plate 12, which at its opposite sideedge is fixed to a side Vplate 13. Said plate 13 at its lower end issecured. rigidly to base frame member 2' and along its lateral'forwardmargin is secured to housing wall 5. Fixed upon said plates 11, 13 andbacking plate 12, and at their upper edges, is a top plate 14, withdepending side skirts 15, 15,' for defining ahoodforming structure whichterminates just forwardly of,

and spacedly above, housing rearwall 7. The portion of machine Aimmediately rearwardlyof housing` rear wall 7 constitutes .an elevatorwell, one side of which is determined by side plate 13 and the oppositeof which is open at B for the feeding therethrough of loaded palletsonto an elevator E adaptedfor reciprocal vertical travel in saidelevator well.

On the inner faces of side plates 11, 13 are aligned verticallydisposedV elevator uid cylinders 16, 16', respectively, the lower endsof which are supported on frame side members 2, 2'; each cylinder 16,16' having a piston 17, which at its upper end is provided with aclevistype mounting 18 for a sprocket 19 about which is trained a chain2d. 'One end of each chain 253 is xed to a bracket 21 on the inner faceof the proximate side plate, while the other end is suitably` secured tothe rearward edge of the adjacent lateral plate 22 of elevator E. Eachlateral plate 22 carries, as by studs, a pair of vertically arrangedrollers 23, 23' (see FigureS) for travel alongY guideways or roller.channels Ziprovided von the inner face of the related side plate. Saidelevator lateral plates 22 are interconnected by a transverse member `25welded at its ends to the inwardly directed faces of said lateralplates. 1 from each lateral plate 22, and being fixed at one of theirends thereto, are parallel arms 26, 236' which attheir Projectingforwardly or lengthwise of frameV forward ends terminate in immediateadjacency to housing rear wall 7; said arms 26, 26' being presentedinwardly of frame side members 2, 2' respectively. On their inward facesarms 26, 26' in their rear portions have mounted thereon alignedbearings 27, 27' respectively, for journaling cf a shaft 28 whichprojects through lateral plates 22 and has keyed or otherwise secured oneach of its extended ends a pinion 29 meshing with a rack 30 provided onthe inner face of side plates 13, 11; said racks 30 and pinions 2,9ooacting to stabilize elevator E during operation thereof.

Carried upon arms 26, 26 and constituting the load receiving surface ofelevator E is a rollered platform comprising a pair of parallel,transversely extending side elements 31, 31' within which are journaledthe ends of a plurality of horizontally spaced apart, rotatable frictionrollers 32; said side elements 31, 31 extending at their ends beyond`arms 26, 2, for,- normal overlying relationship with respect to frameside members 2, 2'. Side elements 31, 31' at one of their ends aresuitable hingedly engaged toarm 26', as at h (see Figure 19), and attheir opposite. ends. are unattachedly supported upon`P the upper edgeof arm 26 s o that the platform will be swingable about its, end remotefrom opening B. Whenk elevator E is. in lowered or full downwardposition arms. 26, 26' will be presented` adjacent frame side members 2,2', with the free ends of side elements 31, 31' being brought intosupported engagement upon stops 33, 33' respectively xed on frame member2 within the. opening B, which will have caused the platform to assumeaninclined attitude, with the other ends, being pivoted` about the hingedengagement with arm 26', for gravity impelled movement ofy palletsthereacross from the feed opening B.

Extending laterally outwardly from the forward edge of rearward sideplate` 1-1isv a flared palletsguide plate 34 for directing of loadedpallets through opening. B and onto elevator E.

`Mounted on sidefplates 11 and 13, toward thefupper ends thereof, arealigned bearingsl 35, 35', respectively,

for-journaling-therein of a shaft 36 extending transverselyktherebetween; one endof said shaft 36 projects outwardly of side vplate11 and has keyed orotherwise securedthereon a speed reduction gear. 37meshing with a drive gear 33 carried on the drive shaft 390i anhydraulicmotor H. Fixed onshaft 36 adjacent bearings 35, 35f 4are sprockets 49,..40', respectively, about whichy areV trained the rear-v ward endportionsof parallel, endless chains 41, 41 respectively, thel forward portionsofwhich are passed about sprockets 4,2, d2' respectively, mountedupon--anf idler shafty 43, journaled at its ends in'bearings 414,y 44'carried at-the'lower ends ofbearingarms45, 45'Yrespectively, .secured-tohoodside skirts 15, 15', respectively, andgldepending Y downwardly belowtheforward end portions thereof; said'shafts 36 and43 ybeing-in axialparallel, planar aligned-relation (seeYFigures-ZandB). Extendingbetweenshafts 36- and 43,V and axially normal theret0 is a pair ofspaced apart stabilizing rods 46, 46 the ends of which `are receivedinrsleeves 47 engaged upon said shafts.

Carried upon endless chains 41, 41'-v is `a pairfof' carton strippers48, 48' Vspaced apart by halffthe length of'said chains 41, 41'y so thatthe same are presented at correspondingly opposite points thereon.Y Eachcarton stripper 48, 48'` comprises a carton-engagingcross rod 49 secured'Carriers 50,. 50 each; mount. a Ufsheped; membervsa. through which therelated chain-,41, 41' will pass, and-the,l base,v of. which member 52engagesv said chains to limit: swinging of the cartonv stripperandhence, stabilize the were?.

Baule under forces applied tocross rod 49, as by cartonsbeing engagedthereby.

Theupper edge of the forward portion of carriers 50,-A

'50' will be presented for stop-wise engagement with the associatedchains 41, 41 so as to limit swinging ofcarton strippers 48, 48 intheother direction; and being primarily engageable with ychains41, 41'intheir upper courses as the carton strippers 48, 48' are beingmoved onthe return or non-operativelportion of the cycle. l

Mounted on elevator E for movement therewith,` asT upon a relativelyshort arm 53,'projecting rearwardly from transverse member is a limitswitch LS-1 havinga triggert'55 (see Figure 6) for sequentiallyengaginga; series of vertically aligned lugs 56 mounted upon a post;y

57 secured to the inner faceof side plate Y171 for eifectingl periodicstoppage of elevator E during its upper travel, for purposes, and in amanner, more fully described hereinbelow; there being a sheaveSSVmounted upon the fmem-p, ber 18 of the adjacent piston 17l fortraining thereabout of a conductor 59 for said switchl LS-l so thatconnection is provided thereto during travel of elevator E.

Projecting laterally from each carrier.50, v50 of cartonl strippers 48,48' is a lug 60 for engaging the trigger 61 of one portion rof aconveyor belt 85, the'upper course of ofy belt 85 beingrtrainedabout abelt roller 87, mounted on an'idler shaft 88 extending between sideframes 66, 70'v adjacent the proximate. end of discharge conveyor D. Itwill-loe noted that driven gear 82 is 'of less diameter than;

a normally open limit switch LS-2fV mounted on side plate 11 adjacentthe upper rearward edge thereof. It will be` seen that such engagementwill Ibe effected atthe com pletion of the return travel of the cartonstrippers 48 orY 48', as the case maybe.

Also carried upon arm 53 is. another normally open limit switch LS-4,having a trigger 62 `engageable byl a lug ,63 extending forwardly fromv'backing plate 12 for termination of downward travel of elevator E,therebyl j causing s-ame to be stopped at its full lower position (as.

shown in full lines in Figure 2). Housing rear wall 7 at its upper endedge is bent forwardly and downwardly to provide a short inclined tongue64 which is substan-f tially planarwise parallel to housing top .wall 9and to which is hingedly mounted the upper end of a slide orv rampvplate 65, the lower or forward end of which is free; said ramp plate 65being of such length that when in its downwardly swung position itslower end will be received upon the upper llange of a channel shapedside frame 66 of a discharge conveyongenerally indicated D', mountedupon top wall 9 of housing 4, and extending thereacross (see Figures land 3). plate 65 and extending downwardly from the Vunderlace thereof isan arm 67 to the lower end of which is'secured' one end of anl extensionspring 68; the other end of said spring 68 being attached to conveyor Dwhereby ramp plate 65 is biased into upper position (see Fig; 2).Mounted on the forwardly presented face of the project- -ing section 7of wall 7 is a normally closed interlock switch IN-l, having a trigger69 for engagement by ramp plate 65 when in loweredpositiomso that bysuch engagement a circuit open condition will be developed.

Discharge conveyor D is inclined transversely of its length at the sameangle as that of the inclination of top' wall 9, namely about 22, andincludes a side frame 70 parallel with side frame 66,*but of relativelyincreased height to provide in its upper portion a carton retaining wallor surface, as at 70. Y Said discharge conveyor D' comprises twojunits,one being a powered roller section,

indicated at 71, and the other, a belt conveyor section,

designated 72. Conveyor section 71 consists of laplurality of frictionrollers 73 journaled'at their ends in side frame 66 and thelower portionof side frame 70; said rollers 73 being arranged in upper and lowervstaggered tiers with a narrow -Aendless belt 74 passing therebetweenand tra-ined about a drum 75 mounted on an idler. shaft;v 76 journaledin be-arings in side frames 66 and 70 at one end thereof; and about adrum 75 securedY on aV powered shaft 77 journaled in bearings providedon side frames 66, 70 at a location beyondtheir intermediate pointtoward the remote end of conveyornD.V LVShaft n77hcarriesKY IntegralwithV ramp l which passes, over a supportplate 86 (see Figure 14)'vextending between side frames66, 70; the other portion gear"78,- for theybelt `conveyor 72 will move at a relatively increased speed to therebyprovide a speed differential between thevconveyor sections 7 1, .7 2.'v

Mounted onfthe outwardly directed face of side plate' 7,0 by'bearings 89is a rocker shaft 90 having engaged thereto, by means of sleeves 91, thelower ends of a plurality ofA upwardly projecting rods92 at the upperends of which arersuitably secured by screws or lugs 93 (see Fig- 'urel2), which extend freely through openings 94 formed in upper portion 70'of side trame 70 and are attached at their projecting ends to a switchrail 95 substantially co-extensive with rollered section 7 v1.kConnecting an adjacent pair (and'preferably aA centralv pair) of rods 92isa dog 96 engaging the trigger 97 of a normally closedinterlockswitchlN-Z carried on the outer face of side frame 70.A For. urgingsaidrail 95 away from side plate 70 and hence, biasing dog 96 intoengagement with switchy IN-2 is a coil `spring 98, one of its endsvbeing-attached. to said dog 96 and the other end being secured to sideframe 70. rDhus, upon force being appliedto rail 95, driving sameagainst side frame 70, las by a carton delivered onto rollered conveyorsection 71, which force is sucient to overcome spring 98, rocker shaft90 will be rotated to cause dog 96 to be moved outwardly away fromswitch lN-2 resulting in circuit-open condition, for

reasons to be described.

`Projecting laterally from side frame 66 near the point of mounting ofdriven gear 82 is a bracket 99 carrying a bearing 100 inwhich issuitably journaled a verticallyV vpresented pintle l101, the upper-endof which extends above side frame 66 and mounts a sleeve 102 foradjustably receiving a switch arm, 103, axially normal to saidv pintle101 and of such length as toextend above theupper coursel of beltconveyor 72 for interjection into the path of cartons carriedtherealong, .with their greatest dimensions being presented crosswiseofthe conveyor. On the lower end of pintle 101 is a plate cam 104 hav-.ing an operating edge 105 for engaging a trigger 106 of a normally openswitch 107; there being a coil spring 108 .engaged at one end to saidcam, at its other end to a bracket 109 on side. frame 66 forurgingpintle 101 into such position tha-'switch arm 103 will be disposed in anaxially perpendicular manner with respect to belt conveyor 72 with cam104 being so related to switch 107- as to maintain same in opencondition.Y rIn circuit with said switch 107 is a solenoid 110 mountedon side lframe 70 having an armature 111v pivotally engaged to a cartondeliector 112 presented v beneath support plate 86 and extending Yat oneend laterally therebeyondv forhinged attachment toV a bracket 113provided Aon side fra-me 70 (see Figure ,144).` An opening 114 isprovided in support plate 86 for reciprocal movement therethrough oftheother end of dveilector 112 on upward movement ofV armature 111 uponenergi'zation of sole- 1 Vno'id 110. Switch arm 103 is of such lengththat the distance from vits innerend to side plate 70V is such astojpermit unimpeded movement therebetween of cartons wherein thewidth-of'the'same isless thanthe distance i between said switcharmf103`and side frame 70. However, said switch arm 103 Vis adapted tobe contacted by. cartogsyvliich are Presented so-as...tc..hve theirgreatest;

dimension crosswise` of the belt conveyor and hence, to cooperate withvde ector 112 to 'effect a 9(l turning of said cartons. The cartoncontacting switch arm 1tl3`will cause same to be swung, overcoming theforce of spring 108 to thereby effectv rotation ofV cam 104' in thedirec,- tion of the arrow shown in Figure l5., whereupon switch 1117`will be closed, resulting in the energization of solenoid 110. This, inturn, causes deflector 1'12 to be moved upwardly through opening 114'into the path of the carton and the deilector 112 will be maintained'`in such position as. long as the circuit is closed., which will' beco-extensive with'the. period in which switch arm 163 is engagedl bytheA carton and: hence maintained; inA swung position. 1t shouldA berecognized that switch arm 1&3 is adapted for over travel so as'to allowpas.- sage of the carton after, same has been turned.` The portion orthe carton striking deflector 112 is detained thereby, with the same,acting as a tu'lcrum since theY undetained or other portion of suchfcarton will beV cartied along by the beltl conveyor 72 and hence,turned4 through an arc off 90. the carton shall have lost contact withswitch arm 103 the latter will beW restored by operation of spring 108to initial position, with consequent opening of' switch 107 andde-energization of solenoid 111i, will return` downward movement ofdeflector 112.

Mounted on the inner face of housing side walls 5,

5, immediately beneath the upper end of top wall 9 are` aligned bearings115, 115 respectively, for journalingN of' a rocker shaft` 116 Whereonisfixed aV pair of generally S-shaped, spaced apart rocker armsv 117,117' which at their lower ends are engagedVA to a reinforcing,connecting rod 11S. Operatively engaging connecting rodv 118, as by aclevis member 119, is the upper end ofthe piston 12@ of a lluid cylinder121- pivotally mounted at its lower end on a bracket 122 vextending fromthe inner face ofv housing rear wall 7. The upperand rear-- wardlyprojectingends of rocker arms 117, 117', extendV through openings 123,123', respectively, formed' inthe' upper portion 7 of housing rear wall7` beneath tongue 6ft; and secured on said projecting ends is a cartonclamping or stabilizing bar 124 of angle shape, having a vertical ieg125 for engaging the forwardly directed surfaces of cartons c on thepallet p to be unloaded, and horizontal leg V126 normally overlyingtongue 64 and eiectively providing an extension of ramp plate 65 whenbar 124 is in operative or rearwardly rocked' position, as shown indotted lines in Figure 9.` Upon flow of fluid-Ato the lower end ofsaidcylinder 121 piston 120, which hasa. relatively short stroke, will be`moved upwardly causing shaft-11e to turn so as to move rocker arms 117,1-17' toward housing rear wall'Y 7; with the upper ends thereof beingcarried to their point otFV maximum projection through openings 12.3,123', thereby presenting carton glampingor stabilizing bar 124 againstthe adjacent endsof the cartons in the next to top tier of cartons onthe pallet to be unloaded (see Figure 2). As the cartons c on the upper'tier are slidingly impelled thereacross under impetus of the 1 cartonstrippers ity or-V 48', the next to top tier of cartons willbestabilizedandhence prevented from moving with the upper tier throughfriction. It will be noted that as thecartons in the top tier arestripped they will move across'the horizontal flange 126 ofV stabilizingbar 1241ery delivery onto slide'or ramp plate 65.

Mounted upon connecting rod 11S is a depending dog 127 for engaging thetrigger 125iv of a normally Vopen limit switch ILS-3 secured on theinner faceV of housing rear wall'7L Conveniently located' within housing4 is a primeY (See Figure 3.) As soon asY Electrical system Withreference now' being made to' the Wiring diagram' shown in Figure 20,the normally open limit switches LS-l, LS-2,4 LS-3, and LS"4 areY inparallel, with their' load sides connected by conductork 3130 to afsolenoid or electro-magnet 301 of' aV stepping switch', Vdesignated'generally at- 302; there being thel customary pla'wl andI ratchet wheel(not shown) for operatively connecting the armature of solenoid 301 withal switchl wiper arm 304 for sequentially engaging stationary terminals'or' contacts C-1, C-Z, C-r, C4'. C-22, and preferably arranged'inasemi-circular bank'. Solenoid' 301 is in circuit'by alead' 3051 to thepositivel terminal off a rectifier 131 of the full wave or bridgetypefor' are connected respectively through leads 308; 309; 310"A and311, to the solenoid coils of relay switches 312; 313, 314, and 315, theother sides of said coils' having a Vcommon connection, namely, lead329, to' lead" 305; Interposed in series in lead 3159 between terminalCL2' and solenoid coil of relay switch 313y are the normallyl closedinteriock switches lN-l, IN-Z'. The load sides of relay switches 312,313, 314, and 315 are respectively:

connected to solenoids 316, 317, 313, and 319 for'actua atingthe valveof a pump P Vfor purposes tolbe described;v Said. solenoids 316, 317,31S and 319 arer connected by" a1 conductor 32.1.to the source ofalternating current'I through a motor starter and disconnect switch'3222 The line sides ofY relay switches 312, 313; 314 and 3151 have acommon connection to lead 323 to the alternati ing current source.

rent control circuitC and, hence, ultimately, the valves' of pump P.

Terminal .Cv-23' on stepping switch 3G2- is connected by a lead 324 toa: normally open, homingV push-button switch 325. connected to aconductor Sttby lead`32I6.v

Rectifier 131Y is connected to the secondary winding of'y a. transformer327'which reduces the line voltage of'thepotential required'y by' 13.1to produce a desired direct current' winding of;

alternating current source to the saidV rectitier voltage' forrcontrolcircuit D. The primary saidV transformer 327' is connected to thealternating current source of switch 322.

The operation of the circuitwi-ll now be described: Assuming elevator Eto be in its bottom or lowermo'st position (full lines,.Figure 2) wiperarrnn'M will be'v in contactwith terminal C-23 (as indicated'by thedotted'y lines at Figure 20) wherebyy no elementv in the direct currentcontrol circuiti) is energized. To commence op-y eration of the systemthe operator, after having closedrr switch 322,'V willclose push buttonswitch 325 thereby completing thecircuit andvmake contact at its otherend with terminal C-1, causing current'to flow through conductor 398,energizing the solenoid coil of relay switch 3.12, efectingenergizaation of pump solenoid 316; whereupon, asV described' morefullyhereinbelow, hydraulic fluid will-be ypumped to the lower end ofelevator uid cylinders 16, 16', with@A the result that elevator Ewillstart its ascent-andcorttinue such until'limit .switch LSl-lt is.momentarily closedW 'by'th'e'rst or lowermost" lug 56`on upright 57`The Said relay switches enablethe'direct' current control circuit Dto'operatez an alternating'v curvv to solenoid 361 so that throughoperationof the paw] and ratchet, -wiperV arm 304 will lose engagement at one ofits ends with terminal C-23 bebr ugh into contact.. wi-thterminal ,QB

ati-sana .9. Vlo.

triggeringjof limitswitch L 1 .energizes-gatepping switch relay,switchesfilZl 313'and 3l4.in therequired sqnc,

solenoid. .with ap u1se.. of. current, thereby eaiisingforfnhloadingfsuecessive tiers.-y Thus, for instance, if the wipenarm304 to.lose.contactl.with terminall and lt o pallet to be unloadedwereto have 7'tiers of'ca'rtons thent there wouldliefZlterrmnls,'thrceffor each tier, on thef eration. a ;di scontinuance ot :the dow; of tli1 rd;,w11l.. 5 3 'switch .302'connected tdrelays 312,313, andV 3 14 asC'fl,vr Y brought about with respecttoelevator cylinders .16,16.,' CL2 and C,-3,`,arej connecte-d and in.multiple With"t he arrestingfthe movement of elevator EQ sincerelaygswitch. latter. However, since the cycle is repetitive, it isdeemedy 312 wi l1-be open, tie-energizing solenoid316. 'I- Iov f'e v er.V unnecessaryto vrepeate the description of the same'ffry relayv switch313 will thenfbe yclosed energizing 1:gu rnp V eachttier; and hence,that'fora Vsingle cycle hasbeen.

solenoidlfl. whereby the'.\ a1ves' y 'o fpumpl?r will beep- 10 deemedadequatetdfully inform as 'to the following eratedto c ause vlluidtoilow tolhydraulic motor'H for operations:A the 'upward` movement ofYelevator E, the Yoperative movement ofthe carton .strippers .48, 48and* stopping of same, vtheoperation of hydraulic motor H,simultaneously, luid: will he delivered to` the lower endlA togetherwiththatofcarton strippers 48, 48 and clamp-, of vtheclamping barcylinder121 foroutwardmovemen ing b ar124,l as described ab0ve ofclamping bar 124 into cartonstabili'zingoroPerative 15 After the lasttier of cartons c uponelevator. E hasl position. Hydraulic 'motor H willcontinue it's'operation beenstripped therefrom and the elevator is atits upper. (except for the action of interlock switches IN-'11, lN -2,most point of travel, bearing an empty pallet "p; momentas willbedescribed), untilthe returning stripper mem-fI ary closure oflimitswitch YLS-'3 at the end of the last Y3.17 vt0beide-energized.;resulting in. Iheswrpsexo ber 48 012:48 causes LS- Zvto b e triggered unloading operation willfcause switch `wiper arm 304to byengagernent thereof w1t l 1. l1 1g 60- F20' be advanced intoengagement with terminal C-22 which;

^ .The cartons C whiChhave been ;unloaded .by Strlppfeffe completes thecircuit yof relay switch 315 with consequent 4 8, 48'pass ove r .r a1r1pl plate 65 Onto discharge C Qllliel'gl"y energizing of .pump solenoid319; the latter causing fluid f. As'ggamp .plate .65 iS, lePre,Sed urldglflle lfdfP-t vtollow into .the upperends ofelevator fluid cylinders16,'. the Cafmfls. it ,Swings 'ilnst ,Spring GS OWDTWBISUY @ndez.-'-1,6".with simultaneous drainage from the lower ends;

effectsL engagement withfinterlock switch the .circuit ofi relay switchj313 Ithereby draulic motori-I; As the cartons pass fromv plate 'ntofydischarge COHVeYOIfD" .they Wills-through, S13-Vit v ;Pl-lSll rent `willagainbe delivered. tostepping switchsolenoid against rail `95 actuatinginterlock. switch IN- 2. sly'lll?A 30.. 301` moving vwiper arm 304 intoengagement withend teralso 013ens the circuit 0f .W1K-Switch '3113!3114.ellvclt minal C-23, stopping .elevator` E in position for receivingstoppage 0f hydraulic mswr Hls'o ,that the Stripping action. dienenloaded einem@ unmading. with wlperarm is* arrested as 'lons @H0115 -areeither 0,11 nl?? Plate. 'f 3,04 .in contact with terminal C-23, thedirect current con- '65 0f abuitlng against fall '95142-Thefclrl1l'tt0.elay trol' circuit D will beopenfwith all components thereof Switch3.1.3 .Wl'be 'r.e'estalllih..rWhen-B59310113llaves 3.illudeenergizedstate. Closure as by lmanual operation,v

bell rleafedv "0 .Pelt CQQVWOT; CHQ-@ urwl?139115? of homing switch'325will thus reactivate the system'for` plate 65 and rail 95 having beenreturnedto their n0r unloading of the pallet.

mal position under influence of the relatedsprings 68,1 98 respectivelyand interlock switches `Ibi- 1 a d INT2 Hydraulic system areagainclosed, withfthe consequent re-energization o f40 kIn Figures 21 to26. the operation of the hyfl solenoid 317 and resumption Vof operation.of hydraulic.. draulic uid system of he present invention isschematimotor H to continue the carton stripping action for recallyfshown. Solenoids 316, 317, 318 and 319 are' moval of the remaining rowsof cartons, on the 4tier being'. mpnu'tedon pump P for `operating thevalves thereof. It stripped., will-be seen that Vthe armatures ofsolenoids 316 and 319 The triggering 0f limit SWlCll LS-z by elrgagemn?45 are oonnectedto opposite extremtiesof a cross bar 330 with lug 60will likewise send alpulse of current'tostepwhich'is centrally pivotallyengaged on a frame ment Ping Ysvllll Solenoid 301'Cval1lslgWiper-@13.304 t0 adber f; Between -thepoint of attachment ofthe armatureVance 'i0 the 1162it terminals namely, Commit .Cl-3, eof solenoid 319andthe pivot point there is engaged toisulting in the de-energizing ofsolenoid317 .with opera-i' bar 330 one end of a connecting link 331, theother end iOll Ofllydraulic mt01'.H .bel1g SOlPed and ClSllre Of 50 ofwhich is swingably connected to the end 'of anvalvejv` relay switch314being effected with consequent energize-r ro'd 332 upon which' aremounted valve cylinders 333i:Y tionfof solenoid 318. This latter willbring about .opera-1 and".33.4 of apump valve Z (Figure 22). Pump valvef-tion of the pump. valves to cause fluid ow tothe top of cylinder .333is positioned for coaction with ports 335,1 clamping bar cylinder 121returning the clamping ,bar 33511 `and 335b,` with portA 335 beingconnected to a j 124 toinoperative or withdrawn. position, ..that.'is, Qutpf. .osupply pipe *.for'Y delivery therethrough of uid from;engagement. with the lcartons `on the pallet to be` un.. pump P.y Port33511 is connected through a conduit 336 loaded. .'I'lie'returnfrockin'gof rocker -arms 117, 1172` with the upper end of elevatonuid cylinders16,' 16'1` willpresent dog 12T f or engagement with ltrigger 'whileport33519l is in communication through a pipe or of limit switch LS-3causing momentary closureof thc1 conduit 337" with the 'lowerends ofsaid cylinders A1` 6',

same so that a pulse of .currentis delivered to; stepping en 16".V Pumpvalve cylinder 334 is positioned for coacti'on switch solenoid 301 withwiper arm 304 .th'ereby, loswith ports 338, 338a and 338b; port 338being connected ing contactwith terminal C3 and being 'advancedlto thefwithpa drain. pipe 339 leading to the liuid reservoir R; next positiontherebeyond, namely, terminal lC-4 with port 338a.being connected by abranch conduit 340 attendant de-energization of solenoid 318 .and'.comme`nce the conduit 337.; while port 3. 38b is' connected by a branch'3 ment of repetition of the described cycle#v Y 65 conduit341 withVconduit 336. Said valve cylinders333' It will be seenthat thesequencehereinabove described andV 334 are .biased by a spring 342 sothat when` solenoids 316l and 319` are simultaneously in deenerjwill befollowed in the removal o f an. entire tier ofcar- Atons c from ,thepallet p being unloadedfso. thatupon., Ygized condition (see Fijgure2l), allports will be closed'.

' switch 3.02 corresponding to, Ean

willfbe .to .eir'ect upward Upon energizing of., solenoid 316 throughthe means heremovement of elevatorE in nderrtofA as there are tiers.ofcartonsto befre'moved Qons'equent. 522)'and Ythus effect awithdrawing'of vvalve rodV 332 to ly',each cycle willrequire three'terminals the stepping.. cause .valve cylinder 333; to block port 335a,` so thatpres d -conne'te fin multiple... Y sreuid may 119W frcmrumpP throushrr'ts 33.52116' .s

with, terminals C-1, C-2, and C-3 Ain order-:lit actuate 75. 33 5 b f ordelivery of fluid vto the lower'endsof cylinders aaaajroa 1 1 16,' 16-for upward travel of elevator E. Upon de-ener gi'zing of solenoid 316both the pump and drain ports 335, 338 lwill be closed as .valvecylinders 333, 334 under inuence of spring' 342 are disposed in closedposition, sothat elevator E will be stoppedV at its particular junctureof ascent. During the operation of machine A solenoid 316 will be, asdescribed above, periodically energized to progressively adm-it pressurelluid to elevator cylinders 16, 16 for travel of elevator E to itsuppermost position. Upon energization of solenoid 319 by closure oflimit switch LS-4 in the manner described, valve rod 332 will be driveninwardly (as will be seen in Figure 23) to cause valve cylinder 333 toclose port 335b thereby allowing ilow of uid from pump P through conduit336 to the upper end of elevator uid cylinders 16, 16', while valvecylinder 334 will close port 3381) to permit the iluid in the lower endof cylinders 16, 16 toV drain through ports 338g and 338 Vto reservoirR, and thereby, effect return or downward travel of elevator E in itslower position.

A similar system is involved in the operation of pump solenoids 317 and318 shown schematically in Figlres 24, 25 and 26; the said solenoidshaving their armatures connected through a pivoted cross bar 343,eccentric link 344 and valve rod 345 to valve cylinders 346 i and 347 ofa valve 343. Said valve cylinder 346 cooperates with ports 349, 349a and349b; port 349 being connected to a supply pipe for deliverytherethrough of the fluid from pump P while port 349a is connected by aApipe 350 to the upper end of clamping bar cylinder 121, with port 34%being connected through a conduit 351 to hydraulic motor H. Valvecylinder 347 cooperates with ports 352, 35251 and 352b; said port 352being connected to the reservoir R while port 352a is in communicationby conduit 353 with the lower end of clamping bar cylinder 121. Saidconduit 353 opens into conduit 351 for purposes presently appearing.Port 352b is connected by -a branch pipe 354 to pipe 359. It will thusbe seen that upon energizing of solenoid 317 (see Figure 25) valvecylinder 346 will close port 349a so that pressure fluid will flow frompump P through conduit 351 and also through conduit 353 so thatsimultaneously hydraulic motor H will be actuated and fluid will bedelivered to the lower end of clamping bar cylinder 121 for driving thepiston 120 thereof upwardly. C ontemponaneously, valve cylinder 347 willclose port 352a so that fluid may drain throughconduits 350 and 354 andports 352b and 352 to the reservoir R from the upper end of clamping barcylinder .121. Upon energization of solenoid 318 (see Figure 26) valvecylinder 346 will close port 349b and valve cylinder 347 will close port35225, in which relationship fluid may flow from pump P through ports349, 34961 to the upper endof clamping bar cylinder 121, the lower endof which will drain through pipe 353 and ports 352a, 352 to reservoir R.ltV must be noted that hydraulic motor H does not have a return linethrough pump P but is connected directly by pipe 355 to reservoir R asmotor H operates in but one direction.

Rsum of operation In view `of Ithe foregoing, it will be seen that apallet p having a load of non-cubic cartons c arranged in tiered, lockedformation (as shown in Figure 3) is fed through opening B in anysuitable manner onto rollered platform. of elevator E which is in itslower position with the platform in inclined attitude, as shown inFigure 19. The operator will then close switch 322 and homing switch325, as, discussed above,r so as to eifect upward movement of elevatorE. Upon the engagement of limit other stripper 48 or 48""will be' at theforward end of the upper course of endless chains 41, 41 preparatory tothe return portion of the cycle. Thus, the thenopex'-l ative cartonstripper 48 will effect engagement between its bar 49 and the cartons inthe rearmost row of the tier to be removed and hence, upon operation ofmotor H will exert a forward pushing action on the whole tier.Y Theforwardmost vrow lwill thus be driven downwardly over ramp plate 65 andonto discharge conveyor D.

.Since ramp plate 65 is forced downwardly interlock switch IN-l will beopened, whereby the carton removing or strippingaction will bemomentarily discontinued until ramp plate 65 and conveyor ysection 71are both cleared. Thus, by the operation of interlock switches IN-l andIN-2 only a single row of cartons will be handled at one time. Thiseiiectively prevents any undesired piling orl jamming of cartons to takeplace, for if the carton strippersA 48, 48' were not arrested or causedto dwell the entire tier of cartons would be forced downwardly towarddischarge conveyor D resulting inan obstructive overloading of cartons con conveyor DWith complete blockage of operation resulting. Furthermore,the inclination of discharge conveyor D is of extreme importance for' itcauses a quick and reliable downward displacement of the cartons so asto'remove same from $0`r` any untoward contact 'with those in the rownext succeeding the tier being stripped.

As shown in Figure 3, such cartons are customarily in locked formationAso that some cartons will be transvferred to conveyor section 71 inaxial alignment thereswitch LS-l by the lowermost lug 56 on upright 57ele- Y vator E 'will be stopped whereupon the top or uppermost tier ofcartons c will be disposed immediately above horizontal flange 126 ofclampingv bar 124,c so that the same may be moved thereacross uponoperation of with, while others will beV axially normal thereto. Theones which are axially normal will hence extend a greater distancetoward the remaining cartons to be removed than the ones which areaxially parallel so that a relatively small extent of clearance ispresent. Accordingly, the i11- clination of conveyor section 71, withits downward component, assures adequate clearance.l It should bepointed out that although reference has'been made herein to rows ofcartons the same, when locked, are not actually in uniform rows due tothe locking character of the stacking pattern.

Cartons c thus transmitted to the end of belt .conveyor section 72 areall in axially aligned relationship as by operation of switch 107 anddeflector 112, and Vare thence discharged ontoV a conveyor section 400,which is transversely, progressivelyv turned through an arc of 22Vu forconnecting discharge conveyor D with a standard, horizontally presented,rollered industrial conveyor 401.

After the top tier of cartons chas been delivered to discharge conveyorD', limit switch LS-2 will be then momentarily closedv by lug 6i) on thereturning carton stripper 43 or 48', as the case may be, sothat, asdescribed above, elevator E will be caused to'resume its upward traveluntil the next lug 56 Von upright 57 has closed limit switch LS-1f Inthis connection Vit must be noted that the spacing between the lugs 56on upright 57 correspond with the height of the cartons to be removedso.that elevator E will travel the requisite distance for presentingeach tier for proper stripping action. Since a machine A would desirablybe utilized for use with cartons of more than 'one height'it is to beconsidered apart of the present invention that lugs 56 on upright 57 maybe disposed thereon in any desired vertical spacing so as to accommodatecartons of varying height, as 4making same removable and henceinsertable within spaced openings (not shown). If desired, a singleupright having about its periphery a plurality of. seriesv of lugs withvarying spacings could be provided,

withsuch upright being rotatable so as to present the Yrequisite seriesof lugs in position for triggering limit switch LS-I.

tiene ftei unloading ofthe pallet p the "same may be re-` moved from thelowered elevator E. by a forklift truckY or may be readily Ydischargedto a pallet stacking machine of the type disclosed in United StatesLetters PatentNo. 2,792,950 issued to Frank W. Fenton and Harold L.Bock,

on May 2l, 1957; with the discharge Vto such machine being effected bythe pushing of the now emptyor unloaded pallet by an incoming loadedpallet.

, It should be understood that changes and ymodifica-V tions in theformation, construction, arrangement, and combination of the severalparts -of the pallet unloading machine may be madeand substituted forlthese herein` shown and described without departing from the, natureand principle of my invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1.,.A pallet unloading machine comprising a frame, a ramp-forming platehingedly mounted in the upper portion of said frame for downwardswingingunder load,

an elevator adapted to support a load-bearing pallet having containersor the like disposed in rowed tiers thereon,V

means for effecting vertical travel of said elevator from the lowerportion of said frame to the upper portion thereof to present theuppermost tier for delivery to said ramp plate, means adapted to operatein timed sequence Yto stoppage of the elevator for pushingly removingthe uppermostI tier of containers from the load and onto Ythe rampplate, and a iixed discharge` conveyor sectionA disposed downwardly andoutwardly of said ramp plate for receiving the containers from the rampplate, said discharge conveyor section and ramp plate having a cornbinedwidth greater thanthegreatest dimension of the containers beingunloaded, said discharge conveyor sections being presented inaxiallyparallel relation to the axis of the rows of containers to beunloaded, said discharge conveyor section being further inclined transversely with its side proximate the ramp Yplate being higher than itsother side and with its length being at least as great as the length ofone row of containers on the pallet to be unloaded for simultaneouslyaccommodat ing the number of row-constituting containers.

2. A pallet unloading machine comprising a frame, a.

ramp-forming plate hingedly mounted in the upper portion of said frame,an elevator adapted to support a loadbearing pallet having containers orthe like disposed in rowed tiers thereon, means for effecting verticaltravel of said elevator from the lower portion of said frame to theupper portion thereof to present the uppermost tier4 from the remoteside of to present the uppermost tier for delivery'lto said plate,Y apusher member for engaging the containers in thel being inclinedtransversely with its side proximate the, Yramp plate being higher saiddischarge conveyor than its side remote therefrom, section having itslongitudinal axis normal to the path of movement of the pusher member,a` container abutment surface. extending upwardly vof said dischargeconveyor section in inclined relationto the vertical, a secondswitchengageable by containerstraveling along said surface for openfordelivery to said ramp plate, a pusher member Vfor' engaging thecontainers in the uppermost tier for effecting transfer of the same fromthe load on to the ramp plate, power means for said pusher member, meansfor actuating said power member to effect operation of said pushermember in timed sequence to stoppage of the downwardly and outwardly ofsaid ramp plate for receiving containers passing therefrom, saiddischarge conveyor section being inclined transversely and axially`normal to the direction of travel of said pusher member, said dischargeconveyor section being aligned with said ramp plate during movementacross the latter of containers delivered thereto by the pusher member,the combined widths of said discharge conveyor Ysection and ramp platebeing greater than the maximum Vdimension of the containers beingunloaded whereby obstructing contact is prevented between containers ona discharge conveyor g section and those at Ythe point of discharge.

3. A pallet unloading machine comprising a frame, a ramp-forming platehingedly mounted in the upper por-Y tion of said frame for downwardswinging under load,

means for normally biasing said ramp plate upwardly, an

load-bearing pallet havingv elevator adapted to support a containers orthe like disposed in rowed tiers thereon, means for effecting verticaltravel of said elevator from the lower portion of said frame to theupper portion thereoffrande for, downward swinging under applied load,means l Y ing the uppermost Vtier of containers from the `load ofcontainers to the ramp plate tainers are disposed upon elevator, and adischarge conveyor section located'spaced .55V

ing the current to said power means, whereby discharging s the dischargeconveyor section. 4. A pallet unloading machine comprising a frame, aramp-forming .plate hingedly mounted in therupper portion of said frame,an elevator adapted to support a load- A i bearing pallethavingcontaincrs or the like tiered thereon,

means for effecting vertical travel of said elevator fromthe lowerportion ofV said frame to the upper portion therey of to presenttheYuppermost tier for delivery to said .ramp plate, a pusher member forengaging the containers in the uppermost tier for effecting transfer ofthe same from the a-discharge conveyor section preis arrested -whilecon- L load on to the ramp plate, power means for said pusher member,means for actuating said power member to eiect operation of said pushermember in timed sequence to stoppage of the elevator, and a dischargeconveyor section located spacedly downwardly of said ramp plate forreceiving containers passing therefrom, said conveyor section having'itslongitudinal axis normal to the direction of travel of said pushermember, and being transversely inclined with its upper side beingproximate the ramp-forming plate and its other or lower side remoteoutwardly therefrom, the axis of said conveyor section being normal tothe path of movement of the pusher member and the width of said conveyorsection being at least as great as one side of the load upon the palletto be unloaded. 5.v A pallet unloading machine as described in claim 4wherein a Vcontainer abutment surface-forming membervv is presentedupwardly extendingly from the lower side of said discharge conveyorsection in inclined relation to the Y vertical'for travel thereagainstof containers on the discharge conveyor section switch means areassociated with said discharge conveyor section, a switch-actuatingmember resiliently mounted on the container-confronting'face ofy saidabutment member for engagement by containers l delivered thereagainst toeiect switch-open condition, said switch and said power meansj beingoperatively connected I so thattsaidpusher member will be arrestedwhile'cori-VV tainers are disposed on said conveyor.

'6, A pallet unloadingmachine comprising a framefa I ramp-plate hingedlymounted on the upper portion of said for normally biasing said rampplateupwardly, `means for supporting a load-bearing pallet havingcontainers or like articlestiered thereon to present the uppermost tierfor delivery on to said ramp plate, a'pusher member for advancon to saidramp plate whereby said latter is forced downwardly, a dischargeconveyor disposed for receiving containers from said ramp plate, a iirstinterlock switch means located for engagement by said ramp plate uponYdown ward swinging thereof,V ak second interlockA switch assoand,l

ciated with said discharge conveyor section for actuation by containersreceived on said conveyor, power means forj eiecting operation of saidpusher member, said power J means, andtrst and second interlock'switches being operatively connected whereby upon engagement of eitheror both of said switches said power means will be arrested so thatoperation of the pusher member will be discontinued while containers areeither on said ramp plate or discharge conveyor section.

7. In a pallet unloading machine, a frame, an elevator adapted tosupport a pallet loaded withk containers or like articles stackedthereon in tieredv arrangement, means for electing vertical travel ofsaid elevator, a pusher member provided on said frame above saidelevator for reciprocal movement toV advance on its operative stroke theuppermost tier of containers from the load, power means for operatingsaid pusher member, a switch carried on said elevator, a plurality ofvertically arranged switchactuating lugs mounted on said frame forsuccessively engaging said switch during travel of said elevator, saidlugs being spaced apart a distance substantially equivalent to theheight of the. individual containers stacked on the pallet, said switchbeing operatively connected to the elevator operating means and saidpower means whereby said elevator will be periodically stopped duringYits upward travel and said pusher member will be activated in timedlsequence to each stoppage ofthe elevator.

8. ln a pallet unloading machine, a frame, an elevator adapted tosupport a pallet loaded with containers or like articles stacked thereonin tiered arrangement, a source of fluid under pressure, first iiuidmeans for effecting vertical travel of said elevator, a pusher membermounted on said frame above said elevator for reciprocal travel .in adirection normal to that of the travel of the elevator for advancing onits operative stroke the uppermost tier o containers from the load,second fluid means for eic-cting operation of said pusher member, pumpmeans, said first and second fluid' means connected by said pump to saidsource of fluid, a switch carried on said elevator, a lug mounted onsaid frame for engaging said switch upon travel of said elevator, saidswitch being operatively connected to said pump means whereby uponengagement of said switch said first fluid means will be arrested andsaid second iluid means actuated' with consequent stoppage of saidelevator and operation of said pusher member in timed relationshipthereto.

9. In a pallet unloading machine as described in claim 8, a secondswitch mounted on said frame, a lug carried on said pusher member forengaging said switch on the return or inoperative stroke of said pushermember, said second switch being also operatively connected to Said pumpmeans whereby upon engagement of said second switch, the operation ofsecond iluid means will be stopped.

- l0. A unit unloading machine comprising a frame, having a horizontaledge portion for delining a discharge point, unit support means providedin said frame for presentation of the units adjacent the dischargepoint, a discharge conveyor section located below and outwardly of saiddischarge point, said conveyor section being inclined transversely ofits length in downwardly and outwardly inclined Vattitude with respectto the discharge point, power means for moving said units from saidsupport means past said discharge point for reception thereof by thedischarge conveyor section, and a switch member physically associatedwith said discharge.

conveyor section for actuation by units received on said conveyorsection, said power means and said switch member being interconnected sothat upon actuation of said switch member operation of the unit movingmeans will be arrested while units are disposed on said dischargeconveyor section.

ll. A unit unloading machine as described in claim 13 and characterizedby said unit support means being horizontally disposed, said dischargeconveyor section having a width slightly greater than the greatestdimension of the units being received thereon for accommodating same inany attitude. Y

1.2. A unit unloading machine as described in claim 10y and furthercharacterized by said discharge conveyor section having its sideproximate the frame being more elevated than its opposite side, a unitabutment surface extending upwardly from the said opposite side of saiddischarge conveyor section in inclined relation to the vertical, andsaid actuating means for arresting operation of the unit moving meansbeing mounted on said abutment surface.

13. A unit unloading machine as described in claim l0 and furthercharacterized by said discharge conveyor section being powered and withits transverse inclination at an angle of 22 degrees to the vertical.

14. A unit unloading machine comprising a frame having a horizontal edgeportion for defining a discharge point, a ramp-forming plate hingedlymounted on said frame at said discharge point for downward swingingunder load, unit support means provided in said frame for presentationof said units at the discharge point, means for moving said units oversaid support means and onto said ramp-plate, and a discharge conveyorsection disposed outwardly and below said ramp plate, said dise' chargeconveyor section being axially normal to the direction of travel of saidunits in moving onto said ramp plate and being inclined transversely ofits length with its side proximate the ramp-plate being higher than itsopposite side.

l5. A unit unloading machine as described in claim 14 and furthercharacterized by means for normally biasing said ramp-forming plate inupwardly presented position, said ramp-forming plate being of suchextent that its outer edge will be brought into abutment upon theadjacent side portion of the discharge conveyor section when saidramp-forming plate is in downwardly swung position under load of unitsmoving thereacross.

16. A unit unloading machine comprising a frame, a ramp-forming platehingedly mounted on said frame for extension therebeyond and fordownward swinging under load, means for normally biasing saidramp-forming plate in upward position, unit support means providedadjacent said ramp plate for presentation of units to be unloadedthereto, unit moving means for effecting transfer of the same from thesupport means to the ramp plate, a first switch engageable by saidramp-forming plate on downward swinging under load for circuit opening,power means for said unit moving means, said irst switch and said `powermeans being connected in circuit so that operation of the latter will bearrested while said ramp plate is in downwardly swung position, adischarge con veyor section presented downwardly and outwardly of saidramp-formingV plate, and being inclined transversely of its length,`with its side proximate the Vramp-forming plate being` higher than itsside remote therefrom, said discharge conveyor section having itslongitudinal axis normal to the path of movement of the unit movingmeans, a second switch provided on said discharge conveyor section forengagement by units traveling therealong for opening the circuit to saidunit moving means whereby delivery of said units to the ramp-formingplate is arrested while units are disposed upon the discharge conveyorsection.

17. A unit unloading machine as described in claim 16 and furthercharacterized by said unit support means being disposed, horizontally,and unit abutment surface extending upwardly from the side of saiddischarge conveyor section remote from said ramp-forming plate, saidsecond switch being mounted upon said abutment surface.

l8..A unit unloading machine comprising a frame, a ramp plate hingedlymounted on said frame for downward swinging under applied load, meansfor normally biasing said ramp plate upwardly, unit support meansprovided in said frame for presentation of the units for unloading tothe ramp plate, unit moving means for advancing the units from thesupport means and onto the ramp'plate, whereby the latter is forceddownwardly under such load, a discharge conveyor section disposed forreceiving units from said ramp plate, a first interlock switch locatedfor engagement by said ramp plate upon downward swinging thereof, asecond interlock switch associated with said discharge conveyor sectionfor actuation by units received on said conveyor section, power meansfor effecting operation of said unit moving means,

having a horizontal edge portion for deining a discharge` point, aramp-forming plate hingedly mounted on said frame at said dischargepoint for downward swinging under load, unit support means provided insaid frame for presentation of said units at the discharge point, powermeans for movingsaid units over said support means and onto said rampplate, aV discharge conveyor` section disposed outwardly of said rampplate, a switch 18 load, means for normally biasing said ramp-formingplate in upward position, unit support means provided yadjacent ksaidramp plate for presentation of units Yto'be unloaded thereto, unitmoving means for eiecting transfer of the same from the support meanstothe ramporming plate, a switch engageable by said'ramp-forming 1'-,yplate on downward swinging under load for circuit opening, .power meansfor said unit moving means, said switch` and said power means beingconnected in circuit so that operation of the latter will be arrestedwhile said ramp-formingplate is 1n downwardly swung position,

and a discharge conveyor section presented outwardly y of saidramp-forming plate.

carried on said conveyor section for actuation by units receivedthereon, said power means and said switch being operatively connected,whereby upon actuation of said switch said power means will be arrestedso that opera-k tion of the unit moving means will bediscontinued whileunits are disposed on said conveyor section.

20. A unit unloading machine comprising a frame, a

ramp-forming plate hingedly mounted on said frame for extensiontherebeyond and for downward swinging under References Cited in the leof this patent UNITED STATES PATENTS Re. 23,103 Newcomer Apr. 26, 19492,314,632 Rear Mar. 23, 1943 2,338,048 Minaker et al. Dec. 28, 19432,479,396 Nelson Aug. 16, 1949 2,500,437 Tandler et al Mar. 14, 19502,608,609 Fitch Aug. 26, 1952 2,644,734 Gabrielsen July 7, 19532,650,333 Taylor Aug. 25, 1953 2,761,542 Pagdin sept. 4, 1956 2,765,102Yohn et al. Oct. 2, 1956 -2,774,489 Guigas Dec. 18, 1956 2,815,846Stevenson Dec. l0, 1957

